John f



J. FQALLElv.v Air Gompresso.v

No. 237,360. Patented Feb. 8,1881.

O o V'l i V f E n o o i Lu L N. PETERS. PHcYD-LITHDGRAPHER. WASHINGTON. D. C.

UNITED 4STATES PATENT OFFICE.

JOHN F. ALLEN, OF BROOKLYN, NEW YORK.

Al RFCOM PRESSO R.

SPECIFICATION forming part of Letters Patent No. 237,360, dated February B, 1881. Application filed May 21, 1879. Patented in England September 29, 1879. i

To all whom it may concern:

Be it known `that I, JOHN F. ALLEN, of Brooklyn, Kings county, and State of New York, have invented new and `useful Improvements in Air-Oompressoraof which the following is a specification. r

The nature of my invention consists, principally, in the combination, with an air-compressing apparatus, of induction and eduction valve or valves controlled in a positive and uniform manner in every part of the movement of such valve or valves by means of a direct connection of such valve or valves with the shaft or a counter-shaftof the prime motor. It also consists `in the arrangement of a heavy reciprocating weight to which the pist0n-rods of both steam and air cylinders are attached, causing them to reciprocate coincident with each other, their throw being limited by their connections with the crank-shaft; and it also consists in a peculiar arrangement for lubricating and cooling the air-compressing cylinder.

In the accompanying drawings, Figure I represents a longitudinal section of an aircompressor embodying my invention. Fig. II is a top view of the same. The other gures represent details, and are referred to in the following description.

Similar letters represent similar parts in all the figures.

Arepresents the air-compressing cylinder, and `IB the steam-cylinder-for operating the same. These cylinders Vare placed one before the,other,`and the pistons of bothwcylinders areattached to one and. thesamepiston-rod, C. At the end of the piston-rod() a heavy weight, D, is attached, to which the connecting-rod E connects, the other end of the rod being connected to the` crank F. rIo simplify the constructionthis heavy weight D is arranged to act as the guide for the end of the piston-rod.

The steam-cylinder B ofthe prime motor is constructed, in the usual manner,with suitable valvesoperated through the eccentric-rods G and H. i

The air-compressing cylinder A is provided i with a slide-valve, J, for theinduetion of the air and suitable ports for the eduction of the same, and having another valve or valves, J l

arranged on the back face for regulating the eduction of the air. For simplicity and cheapness I prefer to seat this last-mentioned valve or valves on the back of `thevalve J. These valves receive positive motion through suitable connecting-rods, L L,whicl1 connect the valvesdirectly with the shaft (or it may be a counter-shaft) of the prime motor, the attach` ment of the rods in this instance `.to the shaft or counter-shaft of the prime motor Vbeingeccentrics.

In all air-com pressing apparatus heretofore devised the valves of the compressing-cylinder for the induction and eduction of the air were either of the self-acting kind operated by the pressure of the air acting underneath them, uncontrolled by any positive motion of the machine itself, or else were at a certain portion ofthe stroke of the piston operated so as'to cause them either to open or shut,`as the case might require 5` but at all other times they were `wholl y uncontrolled by any positive motion, as `was the case of the wholly selfthe ordinary', the apparatus lost all, or nearly all, control of the valves, especially the induction-valves, through their inertia while at rest and their momentum while in motion, andthe air-cylinder would therefore compress less air at a high rate than it would at a low rate of speed.

By the combination, with the air-compressing cylinder, of a positive-motion induction and eduction valve gear the quantity of `air that I am enabled to compress is in directproportion to the speed of the machine, and by the use of heavy reciprocating parts I am enabled to compress the air with a considerable saving of power when the steam-cylinder piston and the air-cylinder piston are upon the same reciprocating piston-rod and the latteris connected direct to the crank-shaft. The part which this heavy reciprocating weight D performs in the economy of power consists in absorbing the force of the steam at the commencement of the stroke, in putting this weight in motion, and returning it at the latter part IOO will be considerable saving of power, as it avoids the transmission of the load through the shaft and the revolving of the latter while under this load, for if the reciprocating parts have but little weight the whole of the force of the steam will be thrown upon the shaft at the commencement of the stroke to get it into the ily-wheel, and at the latter part of the stroke the iy-wheel throws the load upon the shaft again in compressing the air in the cylinder. The diagram represented in Fig. V will illustrate this point under discussion.

Let M N O P Q represent the steam-diagram, and M It S Q that of the air compressed. It will be observed that the force of the steam at the commencement of lthe stroke has very little resistance from the air, and at the latter part of the stroke, where the force of the steam is reduced by expansion, the resistance from the compressed air is greatest. Now, if we have to equalize these forces by means of the fly-wheel, almost all of the steam-force Will have to be thrown upon the shaft and the shaft revolve under this load, which even in moderate-sized cylinders will amount to several tons, a large proportion of which would be lost in friction; but by the employment and use of heavy reciprocating parts the fore part of the steam-diagram, equal to N M X, will be absorbed in the acceleration of the part and given out again at the latter part of the stroke, as X Q Y. Then we should have the diagram N O P Y to compress the air, N MX being absorbed in the acceleration, and X Q Ybeing returned by the momentum of the parts. Engineers will readily observe that by this means heavy y-wheels may be dispensed with and the shaft may be made to revolve nearly in equilibrium instead of' revolvin g it under the entire load.

The valve J to regulate the cduction of the air may be made in a single valve, as shown in Fig. l, or the same may be divided similar to an' expansion-valve in a steam-cylinder. When a single valve is used the line of opening the parts for any desired pressure must be varied either by a link-motion in the valvegear or by advancing or retarding the eccentric upon the shaft. Vhen separate or a divided valve is used the same may be varied and regulated by a'right-and-left-hand screw.

In some cases, where simplicity is desired,

fthe valve at the back of the slide-valveJ may be made self-acting, as shown in Fig. IV, where J represents the slide-valve operated by a positive motion, and J the self-acting valve, made ofleather,india-rubber, canvas, or metal. When but light pressure is required a single valve with considerable amount of lap may be employed. A valve and valve-gear such as patented by me in 1862 and 1869 may be used to considerable advantage for that purpose.

f Fig. III is a cross-section of the air-compressing cylinder, and represents the arrangeme?? oflubricating and cooling the air-cylinder.

T is a reservoir or receiver in which a coil,

W, is arranged, through which water is made to circulate. This reservoir is placed at a lower level than the air-compressing cylinder A. This reservoir is made perfectly tight, and the top is connected, through a pipe, a, with the bottom of the valve-chest, and a pipe, b, leading from the-lower part of said reservoir, is connectedwith the top of the air-cylinder A, or with the eduction-passage.

When the compressor is started a quantity of cooling-liquid, which may consist of oil and water, but preferably water and washingsoda, is introduced into the air-cylinder, together with the entering air, which liquid, after passing through the compressing-cylinder, will be deposited in the reservoir or receiver T, passing through pipe a. After a sufficient quantity has been introduced in this manner this liquid may be made to circulate itself by opening a small cock in the pipe b, as the liquid in the reservoir T is under the pressure of the compressed air, and the upper end of the pipe b is connected either with the induction-passage of the air-cylinder or with the air-cylinder itself. By this means the liquid becomes self-circulating and keeps the compressing-cylinder lubricated, and at the same time cool, as the liquid is cooled by passing over the coil W in thereservoir T, through which a constant stream of cool water is allowed to run 5 or the reservoir T may be placed into a vessel containing cool water. Another advantage derived from this free and continued circulation of liquid into the air-compressing cylinder consists in the fact that this liquid will fill all passage-ways and clearance-spaces in the cylinder, generally called lost space.7 When the compressed air is forced out of the cylinder near the end of said strokes the air will first escape through the valve into its reservoir, while the tluid drawn in at the same time will ll all the spaces, such as at the end of the stroke, between the piston and cylinderhead, as well as the passage-way between the cylinder and the valves,'while only the surplus liquid will be forced through the valve J into the valve-chamber and pass again into the reservoir T. Thislling of all passages and lost spaces with a liquid at the end of each stroke excludes all compressed air from those parts, which, on Ythe return of the piston, would naturally expand again and partly fill the cylinder and reduce the capacity of the cylinder considerably.

lndepen dent of this above-described arrangement of cooling the cylinder, the same may be lined by lining m, made to it only at each end, leaving a space all around the central part, into which water or other liquid may be introduced and made to circulate. The cylinder-heads close the joints between this lining on and the cylinder, and the passages are in this case constructed so as to pass through the cylinder -heads around this joint, as is clearly represented in Fig. l.

What I claim as my invention, and desire to secure by Letters Patent, is-

IOO

IIO

l. In an air-compressing apparatus, the induction-valve ofthe compressin g-cylinder, connected directly with the prime motor by means of a connecting-rod, so that such valve shall always be moved and controlled in a positive and uniform manner, in combination with a seliacting valve for regulating the discharge of the compressed air, substantially as described.

2. In an air-compressing apparatus, the induction-valve of the compressing-cylinder, connected directly With the prime motor bymeans of a connecting-rod, so that such valve shall always be moved and controlled in a positive and uniform manner, in combination with a valve to regulate the discharge of thevcompressed air by opening and closing ports in the back of the former, substantially as described.

JOHN F. ALLEN.

Witnesses HENRY E. ROEDER, J. B. Nouns. 

